powell



May 4 1926.

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A. L. POWELL TRANSIISSION FOR ENGINES Original Filed 8. 1920 11 sheets -sheet 6 ill/I/I/I/ May '4, 1926.

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- UNITED STATES PATENT, OFFICE.

LLVAH. L. POWELL, OF MILES CITY, MONTANA, ASSIGNOR TO -THE A. L. POWELL POWER 00., 01 MILES CITY,

MONTANA, A CORPORATION.

TRANSMISSION FOB ENGINES.

Original 110. 1,384,335, dated July 12, 1921, Serial No. 429,168, filed December 8, 1920. Application for reissue filed March 16, 1923. Serial No.162 5,6 71.

DIVISION A.

To all whom it may concern: Be it known that I, ALVAH L. POWELL, a citizen of the United States, residin at Miles City, in the county of Custerand tate V -.6 of Montana. have invented certain new and 1 625,672 which is a division of this case.

It has been known for many years that a long piston stroke is highly desirable in an internal combustion engine. However it was not practicable to materially increase the sizeof an automobile engine. In automobiles of ordinary construction the diameter of the crank circle is exactly equal to the distance through which the piston moves. It would therefore be necessary to increase the hei ht of the engine two inches for each ad itional; inch of the radius of the crank circle. r

My invention relates to improvements in the transmitting members of engines whereby it is possible to increase the pistontravel without a proportional increase in the dimensions of the engine or motor.

Ithas furthermore been a fact of common knowledge that it would be desirable to decrease the enormous-number of explosions in-the explosivecliamber of an automobile f 'engine. My invention makes it possible to materially decrease thenumber of these ex- "plosions without diminishing the power outut. v p Incidentally my invention by diminishing ithe number of explosions diminishes the overheating of the engine and thereby saves much oil and either diminishes'or eliminates I I many injurious results among which might be mentioned back-firing and the loss of energy through radiation of the heat of the overheated 'engine.-

kEngineers are that a'lon piston stroke would allow a more complete urning of thepxplosive 'gine as a resu t a large part of the power which now escapes in the exhaust is utilized when my improvement is incorporated in ngine strlicture. Likewise it is advan- ..tageous to= havea ilong stroke in a steam expansion of- I in an automobile enthe steam'may be possible. In either an explosive engine or a steam engine my improvement saves much power which is now 5 wasted. v My invention relates to improvements in the transmitting members of engines by which I establish any desired relationbetween the piston travel and the diameter of the crank circle which enables me to obtain advantages in the operation of such engines that are impossible with the construction at present used. My improvement incorporates alever between the pistonand the crank rod. which establishes any desired relation between the piston travel and the diameter of the crank circle so that, while this piston may move, say, six inches, the diameter of the crank circle will be only four.

The lever to which I refer is, therefore, a means for reducing the engine speed, the additional force developed in the longer stroke of the piston enabling the mechanism to transmit greater power to the crank than vapor are mixedand ignited, high speed is the rule. In my invention I am able to reduce this; the additional cylinder space and consequent increase of piston stroke lengthening the interval of movement with reference to time, thus effecting a slowing down of the engine without reducing power. I In all engines intended for high duty this is desirable. Marine engines of the explosion class transmit power to the driving shaftthrough systems of costly gearing which involve greater friction than occurs in the direct connecting gear of reciprocating steam engines. This greater friction is an essential defect in all such power machines.

By using the additional working area in l the cylinder I am able to produce a'further expansion of the charge, with a consequent increase of thermal efiiciency,'- or I mayincrease the volume'oiv the charge and power of the ngine at the same time, securing from=itbe working advantages of an engine of, say, six inch stroke, restricted to a crank circleotfour inches diameter thus raising description to a specific form, embraced in the drawings annexed, but I include in the views covered by the drawings some modifications of the main design, and some applications of my invention to standard types of engines.

Of these drawings:

Figure 1 is an elevation, partly in section, of. the variable movement lever, showing it in connection with a cylinder and crank Bhait.

' Figure 2 is the same at quarter stroke.

Figure 3 is the same at half stroke.

Figure 3 is a diagram showing the various movements involved.

Figure 4 is a transverse sectional view of the lever mechanism.

Figure 5 shows, in section, the variation in position of the connecting rod rack.

Figure 6 is a diagram of the intake, at full stroke.

Figure 7 is an elevation of a modification of the lever mechanism, showing piston at end of downstroke.

Figure 8 is a diagram to show that the leverage may be varied to secure any desired stroke of the piston or throw of the crank shaft.

Figure 9 is a diagram of the power cycle, where the additional area of the stroke is used .for a cooling and retarding means.

Figure 10 is another diagram, to accompuny Figure 9.

Figure 11 is a diagram of a two cycle engine', embracing my variable stroke.

Figure .12 is an elevation, showing a modification .in the arrangement of the crank shaft with reference to the engine cylinder.

the pistgn'movement to that of the crank,

Tamil shew: the full stroke when it is used to allow for Wear.

Figure 13 is a diagram of the relation of.

Figure '19 is alongitudinal section of the same,the parts being shown in elevation.

Figure 20 is a transverse section on the line a,a, Figure 18.

Figure 21 shows a modification of the construction given in Figures 16 to 20, inelusive.

Figure 22 is a longitudinal section of the piston rod shown in Figure 21. V

Figure 23 is a transverse section of the same.

Figure 24 shows an application of my invention to a walking beam steam engine.

Figure 25 represents my lever mechanism attached to the driving gear of a steam locomotive.

Figure 26 represents the cylinder and pistons of a two cycle engine of the double action class, to indicate that my improvement may be applied to such engines, deriving the advantage of power on both sides of the piston.

Figure 27 is a further modification of the yoke-supported rack form of my improvement.

Figure 28. is a sectional view, on the dotted line (Fig. 27) shown with arrows.-

Figures 29- and 30 are diagrammatic, showing the relative proportions of steam cylinders as aiiected by the long stroke of my transmission member. Figure 29 shows the conventional type and Figure 30.shows y yp In Figure 1 the piston A of a gas engine transmits motion through the piston rods, or links, A, A, mounted on a pin, A that passes through the piston walls. These links are held on the pin by means of the bolt shown, and a bushing, A is employed I The links A A connect with crank levers, B, B, by means of pins shown at B The crank levers, B, B, are attached to a pin, B suitably supported in the engine frame. On thesame pin there is asegmental pinion B this pinion and the crank levers B, B,'being keyed to the The segmental pinion B engages pin B a. rack, B that forms part of a. connecting rod B The connecting rod is attached to the shaft crank B", by a wrist pin B, the construction being conventional. Onthe in B there are also swungtwo arms, B which form a support for a slide-bearinginwhich the connecting rod B moves. The arms B are journaled onthe pin B in order to allow free movement with reference to the motion of .the connecting rod, QB. To give proper support to the rod B the arms B B are providedwith a tongue sliding surface, B held in posit-ion by a cap, B, and the tap bolts, B B

Proper wearing surfaces on the rod "B are provided at B, a free sliding roovc for said :rod being furnished.

--ti aa1 at his eonstrmtion given 1 i .segmental the lever B is attached to the dius of the pinion Bf.

vl i ire 4. Under the conditions described it is. evident that on the outstroke of the piston the" lever B swings in an are downward, rotating the pin B and causing the inion to transmit movement to the toothe connecting rod, B. This rod rotates the shaft crank, B, thus transmitting the power developed in the engine cylinder to the engine shaft. The. connecting rod moves in the guiding and retaining means provided by the capped arms, B, B and, the reciprocating motion of the said piston is converted into a movement of rotation at the crank circle. Itwill be noted, however, that iston links A A at a point such that t e eifective length of the lever B is s shown in Figure 1, the ratio of lengths of the lever B to the radiusof the segmental pinion B is approximately two; and the movement of the outer end'B of the said lever B will be greater than that of the engine piston A, from which it derives its motion. Power will be transmitted to the crank B by the racked connecting rod B, from the segmental pinion 2rEF eater than the ra- Referring t Fig. 3 the length of a; QJN is equal to EG, the vertical'distancethrough which any'point on the racked rod moves. Denote by the ratio of the short arm LN to the long arm LB of the lever LB. Then the distance PN equals and h e uals sine (JLB and half the arc QJN,

or J N equals EF, and 7 er LN 1 e uals (angle) JLB (circular measure) This is EF 21'LN JLB x equals (angle) e (JFBT),

cancelling,

W equals (angle) m mircular measure) 'And LN e uals i (circular measure) q (angle) JLB That is, twice the leverage ratio multiplied by the crank throw (in inches) and divided by the piston stroke (in inches) equals the circular measure of half the angle of oscil- Y lation divided by its sine; and the short arm 1 of the lever (in inches) equals the crank i throw (in inches) divided by the circular measure of saidhalf angle. The expression JLB (circular measure) be solved b' the cut and try method, three tria s usually suflicing for the solution.

BH equals 2 X 3.1 cosine Thus of the four essential elements, crank throw, piston travel, length of lever and ratio of short to long arm, any one may be determined when the remaining three are given. These formulas may be expressed in the following form:

BIl equals 2(BlL) cosine [90 (1 In my preferred construction I contem' plate using a crank having a throw of two inches, a pinion having a radius of 1.55 inches and a lever having a length of 3.1 inches. The piston travel may then be computed the last mentioned formula. Evaluating equals 2 X3.1 cosine 16 4 minutes 12 seconds equals 5.95773 inches, 8. value so nearly equal to six inchesthat the difference is mmaterial.

my improved construction it is possible to have a; piston stroke of six inches and a crank d'ismete'rfof four inches, the lower endof the pitman 1& traveling eight inches around thearc B H,,a point on the pitch circle of the pinion B traveling four inches on the are; BLH of the crank lever B being the same .J- and the angle movement as the angular movement MLJ of the pinion B each angle being 147 51"36".

The force developed in a long stroke is in this way compounded into the shorter stroke of a suitably connected crank, the effect heing'a leverage that gives the advantage of a Q six inch working piston stroke while using a four inch'stroke of the Working crank. I

gear the piston movement to increase the force at the crank, the leverage means employed being composed of members of the transmitting means. These means are of a practical and effective form, adapted to long Wear, and are simple with reference to structure.

Considering the crank as the short end of this compound lever and the primary moving element as the long end the circular motionof the short end will be approximate 1y equal to the longer motion of the long end.

It is evident that in an engine cylinder the duration of. piston stroke is a variable quantity, for as the length increases the time of travel increases, other factors being equal. The speed of shaft rotation will therefore be less in an engine of long stroke than in one of short stroke, compression and back pressure remaining the same, but the transmitted power will correspond to the force developed during the piston stroke. Under these conditions this engine will deliver a given h. p.

4'0" poses than that of the direct development of equivalent thereto.

piston stroke is twelve inches.

with a cylinder of given diameter while working at a lower engine speed than would be required by an engine of conventional design. This is accomplished by the extra length of stroke obtained by the lever system interposed between power cylinder and crank shaft. It is universally conceded that reduction of engine speed is of great impor- I tance in engine design.

It is obvious that the proportion of excess stroke over the engine crank diameter may be varied by altering the distance of the pin B or the pitch circle of the pinion B from the center L of their oscillation.

In an engine of this type the additional piston travel may be utilized for other. purpower, but securing thereby advantages Let it be assumed that in an engine of relatively small diameter the The expansive force of the chargewill exert pressure against the piston fora distance and time corresponding to the fall of temperature of the expanding charge, and this will insure power development to a point approximately beyond themiddle of the stroke; that is, for a distance greater than six inches. The piston will, thereafter, travel by the momentum of the crank mechanism, absorbing power from itand acting as a braking, or retarding means, lowering engine 5 ed. At a point in the long stroke a condition of partial vacuum will develop in the cylinder, which will tend to lower the fill temperature ofthe spent gases and,further, lead to an absorption of heat from the cylinder and piston walls. At theend of stroke,

'w'hen theexhaust valve opens, atmospheric n sare will be rss q is i .qyl ncdera d on the down stroke the incoming air will absorb the 'heat from the engine walls. In an engine of'this kind part of the stroke of the piston would develop power, while the remainder would act as a means for removing heat. \Vhile the action was taking place this would involve a loss of power, but the cooling'eifcct on walls and piston would raise the eificiency of the engine as a whole. The point of exhaust would also be near, at or below the atmospheric line, permitting the expansion of the power charge to any desired point or degree.

In Figure 11 I show a diagram of the operation of my differential principle in a two cycle engine. In Figure 5 the positions of'the rack and the lateral positions of the piston rods A --A are shown at extreme points of stroke. Figures 1, 2 and 3 show the positions of the variable stroke members through oncrevolution. Figure 7 shows the same structure as Figures 1, 2 and 3 except that the length of lever arm 13 is considerably greater than the diameter of the pitch circle of the pinion B In Figure 12 I show a novel arrangement of my transmitting members, by means of which I am able to place the center of the crank shaft outside the axis extended of the piston without altering movement or lowering cfiiciency.

A modification of my transmitting members is shown in Figures 1.6, 17 and 18. In this structure I dispense with slide arm B using instead, a guide in the nature of a yoke, C, arranged to press against a loose collar on the pin B As the segmental pinion B? tends to force the rack away, the surface of C, pressing against the collar on B holds it in proper alignment with reference to the movement of the connecting rod B In this construction I employ, preferably, two racks and two segmental pinions, the guide C moving between, as shown in the vertical elevation, Figures 19 and 20, the latter beingascctional view. The guide C is attached to the connecting rod B by' means of tap bolts, as shown at C C In Figures 21, 22, 23, I show a further modification of my transmitting members. In this, I follow the construction given in Figures 16, 1'7, and 18, but in addition thereto I use grooves, D, forming part of the piston rod D and make this rod, rigid, in the position shown. The reciprocating action of the piston causes this rod to press on the rollers I) and'gives motion to the lever cranks 'BB. Y

InFigure 25 I show an application of my invention to the steam engine of a locomotive. Figures 29 and 30 are diagrams indicating the variation of cylinder proportions required to adapt'my invention to such an that of the crank, I lengthen the cylinder in order to be able to efiect a proper cut-off of the steam. By reducing the diameter of the steam cylinder and increasing its length I maintain the same area by changing the vol- It is evident thatmany forms of my invention may be made, and that the propor- Y tions of leverage to stroke can be changed to meet 'various' conditions. I do not limit myself to the exact forms of the invention shown in this application.

What I claim to be novel, and ask to have protected by Letters Patent is:

"1. In a transmission member, the combination of a cylinder, 9. piston in said cylinder,. a lever pivoted in relation to said cylinder and a rod directly connected with said x piston and lever, a pinion ,opera'tively con- 2'. Q20.

nectai with said lever so as to move in unison therewith, and having a pitch radius different from the length of said lever, a rack engaging said pinion, a pivoted movfable guide for holding-said rack in engagement with said pinion and a power shaft rotatable by the movement of said rack.

2. In a transmission member, the combi- 1 nation of a cylinder, a piston in said cylinder, a lever pivoted in relation to said cylinder, means for connecting said piston to said lever, a pinion having a pitch radius different from the length of said lever, means for moving the lever and pinion synchronously a rackengaging said pinion, a pivoted s'dable guide for holding the rack in "engagement with said'pinion and a power shaft rotatable by the movement of said rack, substantially as described.

3. In atransmission member, the combination-0f a cylinder, a piston in said cylinder, a lever pivoted in relation tosaid cylin-= der, a rod connecting said piston and-lever,

V means for connecting said rod to said piston, a pinion of a dilferent radius from the lengthof said'lever, means'for moving the pinion.

and lever synchronously, a. rack engaging saidpinion, a pivoted slidable guide for holding the rack in engagement with said pinioma crank connecting rod forming part ofsaid rack, and a power shaftrotatable by action 'of said crank, substantially as described. U v I 4.1m a power transmission member, the combination of a cylinder, a piston in said evlinder, a rod grooved at its lower end and rigidly attached to said piston, a lever pivcited in relation to said'piston and rod,- a

roller on said lever fitting in the groove of said'rod, a pin supported in the frame of said power tIQDSHllSSlOII- member, a pinion pivoted on said pin, a rack engaging the teeth of said pinion, means for holding said rack in engagement with said pinion, a crank connecting rod forming part of said rack,

and a crank that imparts the motion of said 7 a rack to a power shaft, substantially as described.

5. In a transmission for engines, a cylinder, a piston slidable within said cylinder, a pin, a lever and a pinion mounted on said pin and operatively connected together so as tomove in unison, a connecting rod operatively connecting said piston and lever, ,a

crank, a racked connecting bar adapted to mesh with said pinion and having its opposite end connected with said crank, oscil-' lating means pivoted on said pin and adapted to hold said racked connecting bar' in mesh with said pinion.

6. In a power transmission, a piston, a reciprocating power means directly connected with, said piston, a driven crank, a pin, a lever mounted" on said pin and operatively connected with said reciprocating means, a connecting rod, means operatively connecting said lever and connecting rod whereby the movement of the reciprocating member is equal to twice the length of the lever multiplied by the cosine of an angle equal to minus a fraction whose numerator is the diameter of the crank circle multiplied by 90, and whose denominator is 1r times the radius of the last mentioned means).

7 In a transmission member, the combination of a cylinder, a piston in said cylinder, a lever pivoted in relation to said cylinder, a rod extending from said piston to said lever, means for connecting said rod to said piston, a pimonof a different radius from the length of said lever, means operatively connecting the lever and pinion, a rack, an oscillating guidefor retaining the rack .in engagement with said pinion, a crank connecting rod integral with said rack, and a power shaft rotatable by the action of said crank, substantially as described.

8. In combination, a piston, and an oscillating lever and pinion, moving in unison and driven by thepiston, a crank, a racked connecting rod meshing with the pinion and connected with the crank whereby the piston stroke is equal to twice the length of the lever multiplied by the cosine of anangle equal to (ninety degrees minus a fraction whose numerator is the diameter of the crank circle multiplied by ninety degrees and Whose denominator is 71 times the radius of the pinion). v

9. In combination, a piston, an oscillating lever and pinion, moving in unison and driven by the piston, a crank, a racked connecting rod meshing with the pinion and connected with the crank whereby twice the product of the ratio of the short to the long arm of the lever by the crank throw, all divided by the piston stroke equals half the angle of oscillation divided by half the sine of said angle of oscillation.

In testimony whereof I aflix my signature.

ALVAH. L. POWELL. 

